Disease experts in Canada are watching the latest developments in Europe’s ongoing E. coli outbreak.
The outbreak has killed 36 people and infected thousands of others.
Andrew Potter, director and chief executive officer of the Vaccine and Infectious Disease Organization (VIDO) and InterVac in Saskatoon, said many unanswered questions surround the European outbreak.
“If it (the E. coli strain) was on sprouts in Germany, how did it get there? With E. coli, you don’t usually find it just kicking around on food. You usually find it in animals and I suspect that it (the European case) is not a lot different than the outbreak that they had in spinach in the U.S … where you have a contamination of a crop either due to contaminated water or manure being used as fertilizer.”
Potter said the European case should serve as a wake-up call to disease experts.
Surveillance and monitoring should be stepped up and co-ordinated so that experts better understand the deadly pathogens that could affect human health in different regions.
“This was a big outbreak. It’s got to be one of the world’s largest,” he said.
“It highlights the need for ongoing surveillance so we know what’s out there before it comes and kicks us, like this one did.”
The strain of E. coli responsible for the deaths is unlike any strain previously known in Europe or North America.
E. coli is cylinder-shaped or rod-shaped shaped bacterial species commonly found in the intestines of warm blooded animals.
There are thousands of strains of E. coli, some of which are commonly found in humans and serve a beneficial function.
Other strains, such as the one in Europe, carry a highly toxic protein that can cause severe illness or death.
The European strain was not identified or characterized until a specimen was sent to China and examined by disease experts there.
The origins of the outbreak are also unknown.
European health authorities have identified German-grown vegetable sprouts as a likely vector, but it is unclear how the sprouts became infected.
E. coli outbreaks generally originate from cattle manure or contaminated water.
when contaminated water is used to grow an edible plant crop, Edible plant crops can become contaminated and carry the pathogen to humans when they are grown with E. coli contaminated water.
The use of manure-based fertilizers, which is common in Canada, is another possible source of contamination.
Potter said it’s difficult to increase surveillance of animal and food-borne pathogens because surveillance is costly and government budgets are stretched thin.
Industry has increased efforts in this area, but outbreaks are bound to continue without a co-ordinated global effort.
“Everybody’s looking for something specific, but we’ve got to cast the net a little bit wider and look for the next thing,” Potter said.
“There are literally hundreds of types of E. coli and you can’t look for every single one. Instead, we should focus on what really matters and that’s the pathogen that causes disease in humans.”
VIDO joined a strategic research alliance a few years ago aimed at developing a vaccine that could limit the risk of human disease caused by the potentially deadly E. coli strain O157:H7.
The vaccine, commercialized by the Canadian company Bioniche Life Sciences, was designed to significantly reduce the amount of E. coli O157:H7 shed in cattle manure, thereby reducing the risk of downstream contamination.
Potter said the strain of E. coli that caused the European outbreak has a significantly different structure than O157:H7, making it immune to the effects of the Bioniche vaccine.
“The vaccine that we worked on with … Bioniche would have absolutely no impact on this particular strain because it doesn’t have the (receptor) genes that are needed for (effective vaccination).”
He said it is unlikely that the European outbreak will have direct implications for VIDO operations, but added the organization will continue to monitor the case.
“If there is a link to cattle, then we’ll have a serious look and that may involve us doing some surveillance.”
